Introduction: Dietary therapy is a fundamental component in the management of obesity and type 2 diabetes. However, modifying long-established eating habits remains a considerable challenge. Interventions grounded in Self-Determination Theory (SDT) have demonstrated promising outcomes, and studies conducted in Japan suggest that autonomous motivation for healthy eating is associated with metabolic indicators. Nevertheless, few studies have specifically investigated motivational factors in individuals diagnosed with obesity or type 2 diabetes. To implement SDT-based interventions effectively, it is essential to understand the psychological characteristics related to motivation in these populations.
Objective: This preliminary study aimed to examine the relationships among perceived autonomy support, autonomous motivation for healthy eating, perceived competence for healthy eating, and physical health indicators in individuals with obesity and/or type 2 diabetes.
Methods: Participants were 67 individuals diagnosed with obesity and/or type 2 diabetes (17 men, 49 women, 1 other; mean age = 48.37 ± 1.33 years). Measures included Japanese versions of the Motivation for Healthy Eating Scale, the Perceived Competence for Healthy Eating Scale and the Health Care Climate Questionnaire, and physiological indicators (BMI, waist circumference, blood pressure, fasting glucose, HbA1c, triglycerides, LDL cholesterol, HDL cholesterol).
Results: Perceived autonomy support was significantly associated with autonomous motivation (β = 0.452, p < 0.001), which in turn was significantly associated with perceived competence for healthy eating (β = 0.387, p = 0.002). No significant associations were found for controlled motivation. Perceived autonomy support also directly predicted perceived competence (β = 0.284, p = 0.014). A trend toward a negative association was observed between perceived competence and BMI (β = -0.217, p = 0.083).
Conclusion: Autonomy-supportive care may enhance motivation and perceived competence for healthy eating in individuals with obesity and/or type 2 diabetes, potentially contributing to weight management. Further research with larger samples is warranted.